Drawing on recent work in social philosophy and rational choice theory, in this paper I argue that the core thematic of Kant’s “What is Enlightenment?” is the relationship between reason and constraints. I discuss in some detail Kant’s definition of and distinction between private and public uses of reason. Most generally, I maintain that while Kant’s sense of the private use of reason is too narrowly conceived, his cosmopolitan notion of the public use of reason is far too broad. As a more robust alternative, I propose an account of constitutive constraints and characterize more fully what it means for individuals to make reflexive use of reason vis-à-vis such constraints.
Key words: property, Locke, appropriation, libertarianism, Lockean proviso.
